2023-10-16 20:36:00
Published on October 16, 2023 at 4:36 p.m.
In September 2023, European scientists observed a gigantic hole in the ozone layer above the South Pole. Explanations.
The success of the Montreal Protocol
This is one of the rare environmental successes: the ozone layer above the polar regions is on the mend. By 2019, the hole above Antarctica had reached its smallest size ever recorded. This is thanks, among other things, to the ban on chlorofluorocarbons (CFCs) established in the Montreal Protocol of 1987. The protocol was signed, then applied, by the 195 signatory states two years later.
Two and a half times the size of Canada
However, the trou observed on September 16 was an area of 26 million square kilometers, the size of North America. The ozone layer various above each pole according to the seasons. In winter, holes form because of polar stratospheric clouds which deplete the already limited mass of ozone. In contrast, the ozone level returns to normal in summer. But the ozone hole began to expand rapidly in mid-August, the end of winter for the Southern Hemisphere.
A Herculean volcano
The Hunga Tonga-Hunga Ha’apai volcano could be one of the culprits. Its eruption in the southern Pacific sent more than 50 million tons of water vapor into the stratosphere. El Niño may also have played a role in changing temperatures around the poles. Fortunately, according to experts of the European Space Agency, the ozone layer should still return to normal by 2050.
Ozone: essential to life
All life on Earth is protected by the ozone layer. This acts as an invisible filter that protects all forms of life from overexposure to the Sun’s harmful UV rays. Most UV radiation is absorbed by ozone and therefore cannot reach the Earth’s surface. Without the protective effect of ozone, life on Earth would not have evolved as it did.
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